The general topic of this research is how human infants coordinate their space perception with their actions. Examples of this coordination range from reflexes to complex search behavior, but the research plan focuses on a fundamental problem, how infants use information about self-movement to guide their actions. Specifically, studies are proposed on infants' use of visual and auditory information about self-movement to regulate their reaching, sitting, standing, and walking. The experimental strategy is to measure variations in those behaviors as a function of the kind of information available through perception. The research is consonant with the theoretical position that information available through perception is sufficient to guide even very intricate behavior such as locomotion. The experiments also relate to empirical research on human postural and prehensile control. The aims of the research may be summarized as follows: (1) Study the development of a set of very specific relationships between visual and auditory stimulation and prehensile and postural movements: (2) Compare the contributions that visual and auditory information make to infant postural stability; (3) Investigate the role of experience at sitting and standing in the development of visuomotor postural control; and (4) Assess the distinct contributions of central and peripheral vision to the control of reaching. The research has two important domains of application, the high injury rate among toddlers from falls and the problems of visually impaired children with early motor development.